Worked on enhancing reliability and configurability across two major repositories, ppy/osu-framework and microsoft/git. Addressed a crash in osu-framework’s TextBox by resetting internal state during drag-and-key interactions, and reinforced stability with targeted regression and interaction tests using C# and unit testing practices. Later, delivered a feature for microsoft/git enabling custom GPG program paths, supporting home directory expansion and PATH-based resolution. This involved migrating parsing logic to git_config_pathname and adding comprehensive test coverage for non-absolute paths. Demonstrated skills in configuration management, shell scripting, and system integration, focusing on robust, maintainable solutions that improve developer experience and reduce configuration errors.